In recent years, in a light-emitting display device for a mobile application, a demand for high definition and reduction in power consumption is increasing. As a display device for a mobile application, a liquid crystal display device (LCD), a display device utilizing organic light-emitting diodes (OLED), such as an organic EL display device, an electronic paper, or the like is adopted.
Among them, development of the organic EL display device is gone ahead in order to achieve thinning, high luminance, and increase in speed of the a display panel. The organic EL display device is a display device provided with pixels, each being composed of an organic light-emitting diode, where a response speed is fast because a mechanical action is not required, high-luminance display is made possible because of self-emitting of each pixel itself, and thinning can be made possible because a backlight is not required, so that the organic EL display device is expected as a next-generation display device.
For a pixel circuit for driving a pixel constituting a display portion of the organic EL display device, various configuration have been considered. As one of these configurations, there is a configuration provided with a power line and a power line scanning circuit for controlling the power line in addition to a conventional configuration where signal lines and scanning lines are arranged in a grid pattern (for example, Patent Literature 1 (Japanese Patent Application Laid-Open No. 2007-310311).
The present invention provides a display device that facilitates reduction of a pixel circuit accompanied by high definition. The present invention also provides a display device where a pixel circuit and a peripheral circuit have been simplified. Further, the present invention provides a display device where a process cost has been reduced or a material cost have been reduced.